Be careful when, where you place mulch

Although leaves falling from trees are now providing an abundance of mulch, many other organic materials, such as old hay, manure and compost, are equally valuable.

Lee Reich

Published
12:00 am EST, Friday, November 7, 2003

Laid on top of the ground, any of these organic materials will insulate soil against cold and enrich it with humus, and soften the impact of raindrops. Despite these benefits, you have to be a little careful when and where you lay down mulch.

No special precautions are required where vegetables or annual flowers have been cleared away for the year. Just clean up remains of the garden, then pile on mulch.

Also pile mulch around the bases of trees and shrubs, the sooner the better. Young trees and shrubs benefit the most, their new roots continuing to grow in soil kept warmer by mulch. Active, growing roots can absorb water to replenish that lost through evergreen leaves in winter.

Dont pile mulch right up against the bases of trees and shrubs, though, or trunks may rot. Instead, leave a ring a few inches wide of bare ground between plant stems or trunks and the mulch.

That thick, soft mulch also makes a home for mice. With nearby bark providing food, the animals end up with both food and lodging. Keep mice and voles (meadow mice) at bay by surrounding trunks with a protective barrier such as a cylinder of quarter-inch hardware cloth, or a paper or plastic tree-wrapping material.

How about perennial flowers? Mulch the ground around these plants at anytime. Just pile mulch right on top of perennials that go through winter leafless, but hold off with the mulch on those that are evergreen. Covering green leaves before they are well chilled and dormant will cause them to rot, so wait until cold weather has really set in to mulch evergreen perennials. Next spring, peek beneath the mulch and pull it back as soon as you see new leaves unfurling.

Keep in mind that some perennials dont ever like their crowns mulched. In this group are such plants as coral bells, delphinium, iris, viola, oriental poppies and sedums.

A final use of mulch this time of year is to protect stems of cold-tender woody plants, such as hybrid tea roses in some regions. Again, wait until the weather turns steadily cold before piling mulch up around the stems of these plants, because they do need exposure to some cold to prepare them for winter.